1970 454 Motor Mount Shims - Yes or No?

[Carr C.]

Did the 1970 454 engine use the motor mount shims like the previous year big-blocks?

I see it in the AM, but there is no reference for it in the TIM.

Thanks!

[Dick W.]

Re: 1970 454 Motor Mount Shims - Yes or No?

Carr, it is almost impossible to see the motor mounts let alone the shims. I do not know of a judge that has ever deducted for the presence/absence of them

[Carr C.]

Re: 1970 454 Motor Mount Shims - Yes or No?

Thanks for the reply Dick.

I wasn't neccessarily worried about judging as I was function.

The shims are readily availalbe and cheap, so as I go back I'd like to use them if they should be there.

Anyone?

[Joe L.]

Re: 1970 454 Motor Mount Shims - Yes or No?

Thanks for the reply Dick.

I wasn't neccessarily worried about judging as I was function.

The shims are readily availalbe and cheap, so as I go back I'd like to use them if they should be there.

Anyone?

Carr-----


I believe they were used for 1970, as for previous and subsequent years, but only for big blocks WITH C-60.

[Lyndon S.]

Re: 1970 454 Motor Mount Shims - Yes or No?

Pardon me for being stupid, but I have never heard of motor mount shims? I have heard of motor mount heat shields. is that the same thing here? are is that something different?

[Mike M.]

Re: 1970 454 Motor Mount Shims - Yes or No?

V-shaped stamped steel, about 3/16 thick, inserted between the side of the block and the motor mount. i had a 74 chevy wagon without A/C that had them installed originally. don't recall ever seeing them on c-2 mark 4 engines. mike

[Joe R.]

Re: 1970 454 Motor Mount Shims - Yes or No?

V-shaped stamped steel, about 3/16 thick, inserted between the side of the block and the motor mount. i had a 74 chevy wagon without A/C that had them installed originally. don't recall ever seeing them on c-2 mark 4 engines. mike

Hi Mike:

I have always wondered how these shims affect the motor mount geometry. Aren't the shims the same thickness at all three mounting points?

It seems to me that they would make the effective mounting points on the block "too wide" and would make it hard to get the mounts installed.

It also seems that once installed, the shims would force the rubber isolation material in the motor mount to twist so that it is under stress even with the car at rest.

[Terry M.]

Re: 1970 454 Motor Mount Shims - Yes or No?

I believe the purpose of those shims are to align the fan in the shroud. The C3 w/C60 fan has pointed tips and fits the shroud rather closely.

[Bill C.]

Re: 1970 454 Motor Mount Shims - Yes or No?

All 454 A/C cars (auto or stick) had the shims in them. To align the engine/fan with the shroud.

I can't speak about the "auto" cars and shims being a assembly rule -never came across one of of those yet :-)

The only 454 cars with the "tip" fan are A/C cars, the fan was used from 1970 until 1973. 1970 through better part of 1971 had a small hole and bolt pattern, balance of the years are large hole and bolt pattern.

[Joe L.]

Re: 1970 454 Motor Mount Shims - Yes or No?

V-shaped stamped steel, about 3/16 thick, inserted between the side of the block and the motor mount. i had a 74 chevy wagon without A/C that had them installed originally. don't recall ever seeing them on c-2 mark 4 engines. mike

Mike----


They were supposed to have been installed on 1966-67 Corvette big blocks with C-60, although I doubt that earlier 1966 would have had them. The part number was GM #3894534 and it was uniquely applicable to 66-67 Corvette big blocks.

For 1968, the part number changed to GM #3910756 and this also replaced the 3894534 for 66-67 SERVICE. The 3910756 was used through the 1974 model year for big blocks with C-60.